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Biomedical subjects

J J Hicks

Publications and source records attributed to J J Hicks.

At least 55 records · Page 3Linked to original sources
PubMed1980

Fluorometric detection of implantation sites in rats.

A new fluorescent technique is proposed for detecting implantation sites in the rat, based on the binding capacity of tetracycline. Both intraluminal (20 microgram/kg) and intravenous (8.3 mg/kg) administrations of tetracycline permit the macroscopic visualization (under 366 nm of ultraviolet light) of implantation sites, since they show a lower fluorescence (LFS) than the remaining endometrium (FS). Greater binding of tritiated tetracycline was observed in nonimplantation sites (176 to 56 x 10(3) dpm/mg protein) than in implantation sites (P < 0.05).

Animals↗
PubMed1980

Similar effects of prolactin and dbcAMP upon human spermatozoa metabolism.

Studies were carried out of the effects of prolactin (0.5-1.0 mU) and 3'5' dibutyryl cyclic AMP -(dbcAMP) (100-500 ng) on oxygen uptake and (U-14C) glucose and (1-14C) acetate utilization by human spermatozoa. Both molecules induce a significant increase (P < 0.01) in oxygen uptake when acetate, glucose, pyruvate and lactate were used as substrates, although differences were noted in the induction effect depending on the substrate used (Tukey's multiple comparisons after ANOVA) (P < 0.01). The production of 14CO2 from glucose and labelled acetate was also statistically increased (P < 0.01) by prolactin (from 15.15 to 25.32 nmoles CO2/hour/10(8) sperm cells) as well as by dbcAMP (15.15 to 34.95 nmoles CO2/hour/10(8) sperm cells). From these results we conclude that the activator effects of prolactin and dbcAMP on human spermatozoa with respect to the studied parameters are similar and that prolactin may be an activator of spermatic adenylyl cyclase.

Adenylyl Cyclases↗
PubMed1980

Effect of rabbit spermatozoa on the incorporation of labeled precursors into endometrial macromolecules.

The presence of rabbit spermatozoa in the uterine horn of the doe over a 10-hr period induced an increase in the incorporation of leucine-14C and orotate-3H [from 230 +/- 50 to 520 +/- 32 and 146 +/- 41 to 432 +/- 40 (dpm 10(3) mg DNA; Mean +/- SEM)] into endometrial proteins and nucleic acids. The addition of actinomycin D or cyclohexamide significantly inhibited this process. The intraluminal administration of dibutyryl cyclic AMP (dbcAMP) (control group) induced an increase two times greater than that produced by spermatozoa. The increase in the incorporation of radioactive precursors into endometrial macromolecules induced by the spermatozoa is independent of the uterine carbonic anhydrase activation produced by this cell.

Animals↗
PubMed1980

High resolution cytochemical study of uterine epithelial cell surface of the rat at identified sites previous to blastocyst-endometrial contract.

A transmission electron microscopy study was carried out in prospective implantation sites in uterine horns of rats of the Long Evans strain. The purpose was to search for possible modifications in glycoproteins of outer coats of endometrial epithelium shortly before blastocyst-endometrial contact Shea's technique (Lanthanum-Alcian blue) was used to visualize glycoproteins. Prospective implantation sites disclosed a rather thin finely granular electrondense layer along the plasma membrane of the surface endometrial cells. In addition, there was a decrease in the number of microvilli as well as a lack of Lanthanum precipitate in junctional complexes. Sites remote from prospective implantation areas, disclosed a thicker electrondense layer of glycoproteins in cell plasma membranes including those of well developed microvilli. The junctional complexes were well depicted by the electrodense lanthanum salt precipitates. These observations suggest that a mechanism other than a more physical contact take place and induce the above changes.

Animals↗
PubMed1979

Inhibition of implantation by intraluminal administration of concanavalin A in mice.

Important characteristics of endometrial implantation sites are the changes of polarity and molecular composition of the cellular surface. For this reason the masking of surface carbohydrates could lead to an inhibition of the recognition by the blastocyst of the endometrial implantation site. Considering the impact of lectins on carbohydrates, we decided to utilize the intraluminal administration (5 microliter) of different concentrations of concanavalin A (15-60 microgram) in pregnant female mice in the preimplantation phase. An inhibition of 100% of implantation wqs obtained with concentrations of 30 and 60 microgram of the lectin administered on days 3 and 4 of the pregnancy (P less than 0.001). Less important effects were observed on administering 15 or 20 microgram of the lectin (73 and 87% of inhibition) and on utilizing the different doses on days 1 and 2 of the pregnancy. Thus, we conclude that the egg must recognize certain molecules of the endometrial surface (alpha-D-mannopyranose and alpha-D-glucopyranose) in order to implant and that the making of these sites potentially constitutes a new contraceptive approach.

Animals↗
PubMed1978

Lactate and pyruvate utilization by the spermatozoa of infertile human males.

In studying the metabolic pathway of lactate and pyruvate in human spermatozoa from fertile and infertile subjects, pyruvate 1-C14 and lactate 1-C14 were used as substrates in a radiorespirometry system. Spermatozoa from patients with 20 +/- 2.0/10(6) spz/ml and decreased motility (group B) showed a more active decarboxylation of both pyruvate 1-C14 and lactate 1-C14 with a higher production of lactate C14, oxaloacetate, citrate, and isocitrate than those from fertile normal subjects (group A). Spermatozoa from fertile patients with normal counts but low motility (35 +/- 2.0% +++ motility) showed a similar rate of decarboxtlation of pyruvate 1-C14 but a greater rate of decarboxylation of lactate 1-C14 than those from fertile subjects. The low utilization of pyruvate by the spermatozoa from group C infertile patients, with intermediate counts and motility could be explained by a metabolic failure similar to that produced by some inhibitors of the respiratory chain. We do not have an explanation for the metabolic behavior observed in spermatozoa from group B patients, and further research on this point is desirable.

Adult↗
PubMed1978

[New concepts related to implantation. III. Biochemical characteristics].

The fixed position of trophoblast in the uterus is preceded by zygote orientation and its contact, adhession and fusion with endometrial cell membrane. These interactions take place in a precise site called "implantation site". The identification of this area by the administration of pontamine blue has allowed biochemical studies which showed an increase (in the site) of glycolytic enzymes activity of the pentose cycle, of beta-glucuramidase and of acid and alkaline phosphatase; with a decrease in catepsine D activity. In non implanted tissue, isocitric dehydrogenase activity is decreased. From the biochemical standpoint the implanted endometrium may be different from the rest, which allows a better knowledge of possible molecular mechanisms related with implantation, as well as the possible inhibition with medication.

Blastocyst↗